<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css" rel="stylesheet">
</head>
<body>
    <div class="container">
        <h2>按钮</h2>
        <button class="btn btn-default">按钮</button>
        <button class="btn btn-primary">按钮</button>
        <button class="btn btn-info">按钮</button>
        <button class="btn btn-success">按钮</button>
        <button class="btn btn-danger">按钮</button>
        <i class="glyphicon glyphicon-asterisk"></i>
        <i class="glyphicon glyphicon-heart"></i>
        <i class="glyphicon glyphicon-headphones"></i>
      <h2>按钮快进</h2>
        <button type="button" class="btn btn-default" aria-label="Left Align">
            <span class="glyphicon glyphicon-fast-backward" aria-hidden="true"></span>
        </button>
        <button type="button" class="btn btn-default" aria-label="Left Align">
            <span class="glyphicon glyphicon-fast-forward" aria-hidden="true"></span>
        </button>
                  
        <h2>下拉菜单</h2>
        <div class="dropdown">
            <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="true">
                  Dropdown
                <span class="caret"></span>
            </button>
            <ul class="dropdown-menu" aria-labelledby="dropdownMenu1">
                <li><a href="#">Action</a></li>
                <li><a href="#">Another action</a></li>
                <li><a href="#">Something else here</a></li>
                <li role="separator" class="divider"></li>
                <li><a href="#">Separated link</a></li>
            </ul>
        </div>
        <h2>按钮组</h2>
        <div class="btn-group" role="group" aria-label="...">
            <button type="button" class="btn btn-default">Left</button>
            <button type="button" class="btn btn-default">Middle</button>
            <button type="button" class="btn btn-default">Right</button>
        </div> 
        <h2>按钮下拉菜单</h2> 
        <div class="btn-group">
            <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                Action <span class="caret"></span>
            </button>
            <ul class="dropdown-menu">
                <li><a href="#">Action</a></li>
                <li><a href="#">Another action</a></li>
                <li><a href="#">Something else here</a></li>
                <li role="separator" class="divider"></li>
                <li><a href="#">Separated link</a></li>
            </ul>
        </div>
        
    </div>



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</body>
</html>